1. Field of the Invention
The object of the invention is the method of controlling pH of the medium in the fermentation processes in an aqueous medium and a reactor for carrying out this process. The object of the invention can be used in electrolytic processes of fermentation carried out in an aqueous medium.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
The systems used to carry out fermentation with microorganisms are made of reactors connected with the devices providing controlled conditions for the growth of microorganisms. In these systems the parameters such as: pH and availability of nutrients are adjusted using a set for dispensing fluids (gases or liquids) overcoming certain medium changes caused by the activity of microorganisms.
A microbiological culture is often accompanied by a change of pH resulting from producing acidic or alkaline substances or getting them from the substrate. Because, to a large extent, life processes of microorganisms depend on the growth conditions, pH should be adjusted in order to maintain culture performance.
In the standard approach, adjustment of pH of the medium while carrying out fermentation processes is based on the system consisting of a sensor (glass electrode with a pH meter) connected to a decision-making unit (microprocessor system) and a peripheral device (pump) metering a concentrated solution of a neutralizing agent (acid or base). The neutralizing agent is fed to the reactor if the sensor registers exceeding the setpoint by the operator.
U.S. Pat. No. 7,250,288B2 shows the concept of using the electrodes with immobilized biological catalyst (whole microorganisms or enzymes) as a method for providing reduction power for conducting enzymatic reactions or fermentation processes.
U.S. Pat. No. 5,443,706A uses a similar solution for treating wastewater of nutrients. The reactor equipped with an appropriate set of electrodes was used for the biological reduction of nitrate into free nitrogen from aqueous solutions using the reduction power provided by the electrodes. Thanks to the same solution, it was also possible to produce methane through carbon dioxide reduction. Both processes used cultures of microorganisms of appropriate metabolic capacity.